Last season, it was just before the regular season started that the Pistons found out about Reggie Jackson’s tendinitis in his knee and thumb. This season, the news of his severe ankle sprain was a belated lump of coal on the day after Christmas.

The Pistons’ promising 19-14 start cratered into a 12-25 stretch that essentially dented their playoff chances for the second straight season.

When Jackson is healthy, the Pistons have the look of a playoff team; when he’s out, they seem destined for the draft lottery.

While many fans clamored for a Jackson replacement — either through trade, free agency or the draft — all signs point to Jackson sticking around to finish the last two years of his five-year contract for $80 million.

This season, they were 27-18 with him in the starting lineup; that plus-9 margin in their record is significant. If they would have been just 18-19 in the games that Jackson missed, they would have finished 45-37 — which would’ve been good enough for the No. 6 seed in the East.

Those are hypotheticals, but it shows Jackson’s value to the Pistons. After the addition of Blake Griffin as another primary ballhandler, they showed some of their potential with the pair playing together, but it was limited to a four-game sample size because of Griffin’s ankle bruise, causing him to miss the last eight games. When the two played together, the Pistons were 3-1, with the only loss coming in overtime at Houston.

“It’s about getting healthy once again in the offseason and getting back to training,” Jackson said. “I just want to be healthy again. (His healthy is) still not fully right, but it’s to the point where I can play and manage things. It’s about being healthy again coming into the offseason.

“It’s holding up; I wish it could be better. It’s holding up and I think it was expected by the doctors and training staff who told me not to expect feeling back to being (myself). I’ve been able to manage it.”

Jackson, who turned 28 last week, wasn’t quite himself before the injury, but shot 34 percent on 3-pointers and averaged 14.6 points.

More than anything, he was a pick-and-roll threat with Drummond and his playing off the ball more enabled the offense to be more diverse.

“I missed 30-something games at the end of the season,” Jackson said. “I don’t think anybody can shoot what they normally shoot.”

When he returned from the injury, Jackson wasn’t quite as effective, hitting just 22 percent from beyond the arc and struggling to find his touch, both in the lane and on 3-pointers. At times, he relied on the jump shot too much; at others, he didn’t have the burst to create separation on drives to the basket.

“Where it showed up more than anything this year was in his shooting, even before he went down,” coach Stan Van Gundy said. “He played well but his 3-point shooting has been down all year and I attribute that to the fact that he wasn’t in the gym in the summer like he normally is.

“Reggie is a guy who spends a lot of time and has great pride in his game and he was not able to do that.”

In the offseason, Jackson will look to continue strengthening his right ankle, but also get a full slate of strenuous workouts in to test it and return with a full level of confidence in the knee and ankle.

The summer maintenance is critical, but also paying attention to warning signs and smaller issues during the season will be key to preventing another long-term absence. While that could mean the Pistons look more to ensure against another lapse with another point guard; the more likely option is that Griffin is that other ballhandler.

“For Reggie, he’s doing a good job staying on his body and keeping himself fresh. When he does feel something, he needs to take time off and relax,” Drummond said. “He’s done a good job of getting himself back to where he needs to. He took the time he was away seriously to get his body right.”

As for the Pistons’ future and the plan ahead for Van Gundy, Jackson isn’t making any predictions but is ready to face whatever next season brings.

“I’m a little older and wiser; I can only control what I can control. I love basketball; God allows me to come back and play, I’ll come back and play,” he said.

“If we have our coach, we have our coach. I’m not (Gores); I just play.”